Without limiting the scope of the invention, its background is described in connection with tiltrotor aircraft.
A conventional tiltrotor aircraft configuration can include a fixed engine with a rotating proprotor; however, conventional packaging arrangements of the fixed engine and the rotating proprotor can have significant shortcomings. Further, the location of the fixed engine and the rotating proprotor in relation to each other, as well as to the wing structure, can have significant influence upon the size and weight of the supporting structure, as well as the complexity of servicing procedures. For example, a rotating proprotor that is cantilevered outboard of the tip end of the wing can require significant structure to adequately support and prevent operationally induced deflection. Further, a rotating proprotor embedded in the wing structure can be difficult and time-consuming to perform maintenance thereon. Likewise supporting the engine at the wingtip in a nacelle can add significant structural weight and complexity to the wing/rotor pylon configuration.
Hence, there is a need for mounting an engine of an aircraft within a fuselage in order to simplify rotor pylon and nacelle configuration, reduce space constraints, and/or reduce aircraft moment of inertia for improved maneuverability.